Articular cartilage provides a smooth mechanical surface and cushion at skeletal sites subjected to repetitive friction and high weight-bearing loads. In humans, articular cartilage is a relatively thin (<2 mm thick), avascular and acellular tissue located at the proximal and distal ends of the axial skeletal bones. Consequently, articular cartilage has little capacity for self repair [McPherson J M, Tubo R. 2000 in Principles of Tissue Engineering, Second Edition edit Lanza RP, Langer R, Vacanti J. Academic Press, San Diego, p 697–709]. Articular cartilage fractures occur in patients who have fallen and have absorbed the force of the impact directly across a joint space (knee, hip, or elbow). Upon examination, orthopedists routinely discover that the articular cartilage has broken into multiple fragments that may or may not remain adherent to the underlying bone scaffold. Orthopedists have few available alternatives for the treatment of these defects; these include debridement, osteochondral grafting, and mechanical supports [McPherson J M, Tubo R. 2000 in Principles of Tissue Engineering, Second Edition edit Lanza RP, Langer R, Vacanti J. Academic Press, San Diego, p 697–709].
Traumatic injuries to joints in adults are typically the result of a compressive force across the articular surface. This can lead to irreversible damage to the cartilage accompanied by comminution and/or depression of articular fragments. Convex surfaces such as the tibial plateau, distal radius and acetabulum are most often affected. Once the major bone/cartilage fragments are re-approximated and stabilized with plates and screws, the orthopedist is still faced with an as yet unsolved challenge, the resurfacing of residual articular defects with healthy, viable cartilage.
What is needed are compositions and methods for the repair or replacement of articular cartilage fractures utilizing tissues and compositions that allow for the re-growth of damaged or missing cartilage.
Therefore an object of the invention is to provide methods and composition for the use of isolated adipose tissue-derived adult stem or stromal cells in the repair of articular cartilage fractures and defects.